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 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package java.net;

import java.io.ObjectStreamException;

/**
 * This class represents an Internet Protocol version 4 (IPv4) address.
 * Defined by <a href="http://www.ietf.org/rfc/rfc790.txt">
 * <i>RFC&nbsp;790: Assigned Numbers</i></a>,
 * <a href="http://www.ietf.org/rfc/rfc1918.txt">
 * <i>RFC&nbsp;1918: Address Allocation for Private Internets</i></a>,
 * and <a href="http://www.ietf.org/rfc/rfc2365.txt"><i>RFC&nbsp;2365:
 * Administratively Scoped IP Multicast</i></a>
 *
 * <h3> <A NAME="format">Textual representation of IP addresses</a> </h3>
 *
 * Textual representation of IPv4 address used as input to methods
 * takes one of the following forms:
 *
 * <blockquote><table cellpadding=0 cellspacing=0 summary="layout">
 * <tr><td>{@code d.d.d.d}</td></tr>
 * <tr><td>{@code d.d.d}</td></tr>
 * <tr><td>{@code d.d}</td></tr>
 * <tr><td>{@code d}</td></tr>
 * </table></blockquote>
 *
 * <p> When four parts are specified, each is interpreted as a byte of
 * data and assigned, from left to right, to the four bytes of an IPv4
 * address.

 * <p> When a three part address is specified, the last part is
 * interpreted as a 16-bit quantity and placed in the right most two
 * bytes of the network address. This makes the three part address
 * format convenient for specifying Class B net- work addresses as
 * 128.net.host.
 *
 * <p> When a two part address is supplied, the last part is
 * interpreted as a 24-bit quantity and placed in the right most three
 * bytes of the network address. This makes the two part address
 * format convenient for specifying Class A network addresses as
 * net.host.
 *
 * <p> When only one part is given, the value is stored directly in
 * the network address without any byte rearrangement.
 *
 * <p> For methods that return a textual representation as output
 * value, the first form, i.e. a dotted-quad string, is used.
 *
 * <h4> The Scope of a Multicast Address </h4>
 *
 * Historically the IPv4 TTL field in the IP header has doubled as a
 * multicast scope field: a TTL of 0 means node-local, 1 means
 * link-local, up through 32 means site-local, up through 64 means
 * region-local, up through 128 means continent-local, and up through
 * 255 are global. However, the administrative scoping is preferred.
 * Please refer to <a href="http://www.ietf.org/rfc/rfc2365.txt">
 * <i>RFC&nbsp;2365: Administratively Scoped IP Multicast</i></a>
 * @since 1.4
 */

public final
class Inet4Address extends InetAddress {
 final static int INADDRSZ = 4;

 /** use serialVersionUID from InetAddress, but Inet4Address instance
 * is always replaced by an InetAddress instance before being
 * serialized */
 private static final long serialVersionUID = 3286316764910316507L;

 /*
 * Perform initializations.
 */
 static {
 init();
 }

 Inet4Address() {
 super();
 holder().hostName = null;
 holder().address = 0;
 holder().family = IPv4;
 }

 Inet4Address(String hostName, byte addr[]) {
 holder().hostName = hostName;
 holder().family = IPv4;
 if (addr != null) {
 if (addr.length == INADDRSZ) {
 int address = addr[3] & 0xFF;
 address |= ((addr[2] << 8) & 0xFF00);
 address |= ((addr[1] << 16) & 0xFF0000);
 address |= ((addr[0] << 24) & 0xFF000000);
 holder().address = address;
 }
 }
 holder().originalHostName = hostName;
 }
 Inet4Address(String hostName, int address) {
 holder().hostName = hostName;
 holder().family = IPv4;
 holder().address = address;
 holder().originalHostName = hostName;
 }

 /**
 * Replaces the object to be serialized with an InetAddress object.
 *
 * @return the alternate object to be serialized.
 *
 * @throws ObjectStreamException if a new object replacing this
 * object could not be created
 */
 private Object writeReplace() throws ObjectStreamException {
 // will replace the to be serialized 'this' object
 InetAddress inet = new InetAddress();
 inet.holder().hostName = holder().getHostName();
 inet.holder().address = holder().getAddress();

 /**
 * Prior to 1.4 an InetAddress was created with a family
 * based on the platform AF_INET value (usually 2).
 * For compatibility reasons we must therefore write the
 * the InetAddress with this family.
 */
 inet.holder().family = 2;

 return inet;
 }

 /**
 * Utility routine to check if the InetAddress is an
 * IP multicast address. IP multicast address is a Class D
 * address i.e first four bits of the address are 1110.
 * @return a {@code boolean} indicating if the InetAddress is
 * an IP multicast address
 * @since JDK1.1
 */
 public boolean isMulticastAddress() {
 return ((holder().getAddress() & 0xf0000000) == 0xe0000000);
 }

 /**
 * Utility routine to check if the InetAddress in a wildcard address.
 * @return a {@code boolean} indicating if the Inetaddress is
 * a wildcard address.
 * @since 1.4
 */
 public boolean isAnyLocalAddress() {
 return holder().getAddress() == 0;
 }

 /**
 * Utility routine to check if the InetAddress is a loopback address.
 *
 * @return a {@code boolean} indicating if the InetAddress is
 * a loopback address; or false otherwise.
 * @since 1.4
 */
 public boolean isLoopbackAddress() {
 /* 127.x.x.x */
 byte[] byteAddr = getAddress();
 return byteAddr[0] == 127;
 }

 /**
 * Utility routine to check if the InetAddress is an link local address.
 *
 * @return a {@code boolean} indicating if the InetAddress is
 * a link local address; or false if address is not a link local unicast address.
 * @since 1.4
 */
 public boolean isLinkLocalAddress() {
 // link-local unicast in IPv4 (169.254.0.0/16)
 // defined in "Documenting Special Use IPv4 Address Blocks
 // that have been Registered with IANA" by Bill Manning
 // draft-manning-dsua-06.txt
 int address = holder().getAddress();
 return (((address >>> 24) & 0xFF) == 169)
 && (((address >>> 16) & 0xFF) == 254);
 }

 /**
 * Utility routine to check if the InetAddress is a site local address.
 *
 * @return a {@code boolean} indicating if the InetAddress is
 * a site local address; or false if address is not a site local unicast address.
 * @since 1.4
 */
 public boolean isSiteLocalAddress() {
 // refer to RFC 1918
 // 10/8 prefix
 // 172.16/12 prefix
 // 192.168/16 prefix
 int address = holder().getAddress();
 return (((address >>> 24) & 0xFF) == 10)
 || ((((address >>> 24) & 0xFF) == 172)
 && (((address >>> 16) & 0xF0) == 16))
 || ((((address >>> 24) & 0xFF) == 192)
 && (((address >>> 16) & 0xFF) == 168));
 }

 /**
 * Utility routine to check if the multicast address has global scope.
 *
 * @return a {@code boolean} indicating if the address has
 * is a multicast address of global scope, false if it is not
 * of global scope or it is not a multicast address
 * @since 1.4
 */
 public boolean isMCGlobal() {
 // 224.0.1.0 to 238.255.255.255
 byte[] byteAddr = getAddress();
 return ((byteAddr[0] & 0xff) >= 224 && (byteAddr[0] & 0xff) <= 238 ) &&
 !((byteAddr[0] & 0xff) == 224 && byteAddr[1] == 0 &&
 byteAddr[2] == 0);
 }

 /**
 * Utility routine to check if the multicast address has node scope.
 *
 * @return a {@code boolean} indicating if the address has
 * is a multicast address of node-local scope, false if it is not
 * of node-local scope or it is not a multicast address
 * @since 1.4
 */
 public boolean isMCNodeLocal() {
 // unless ttl == 0
 return false;
 }

 /**
 * Utility routine to check if the multicast address has link scope.
 *
 * @return a {@code boolean} indicating if the address has
 * is a multicast address of link-local scope, false if it is not
 * of link-local scope or it is not a multicast address
 * @since 1.4
 */
 public boolean isMCLinkLocal() {
 // 224.0.0/24 prefix and ttl == 1
 int address = holder().getAddress();
 return (((address >>> 24) & 0xFF) == 224)
 && (((address >>> 16) & 0xFF) == 0)
 && (((address >>> 8) & 0xFF) == 0);
 }

 /**
 * Utility routine to check if the multicast address has site scope.
 *
 * @return a {@code boolean} indicating if the address has
 * is a multicast address of site-local scope, false if it is not
 * of site-local scope or it is not a multicast address
 * @since 1.4
 */
 public boolean isMCSiteLocal() {
 // 239.255/16 prefix or ttl < 32
 int address = holder().getAddress();
 return (((address >>> 24) & 0xFF) == 239)
 && (((address >>> 16) & 0xFF) == 255);
 }

 /**
 * Utility routine to check if the multicast address has organization scope.
 *
 * @return a {@code boolean} indicating if the address has
 * is a multicast address of organization-local scope,
 * false if it is not of organization-local scope
 * or it is not a multicast address
 * @since 1.4
 */
 public boolean isMCOrgLocal() {
 // 239.192 - 239.195
 int address = holder().getAddress();
 return (((address >>> 24) & 0xFF) == 239)
 && (((address >>> 16) & 0xFF) >= 192)
 && (((address >>> 16) & 0xFF) <= 195);
 }

 /**
 * Returns the raw IP address of this {@code InetAddress}
 * object. The result is in network byte order: the highest order
 * byte of the address is in {@code getAddress()[0]}.
 *
 * @return the raw IP address of this object.
 */
 public byte[] getAddress() {
 int address = holder().getAddress();
 byte[] addr = new byte[INADDRSZ];

 addr[0] = (byte) ((address >>> 24) & 0xFF);
 addr[1] = (byte) ((address >>> 16) & 0xFF);
 addr[2] = (byte) ((address >>> 8) & 0xFF);
 addr[3] = (byte) (address & 0xFF);
 return addr;
 }

 /**
 * Returns the IP address string in textual presentation form.
 *
 * @return the raw IP address in a string format.
 * @since JDK1.0.2
 */
 public String getHostAddress() {
 return numericToTextFormat(getAddress());
 }

 /**
 * Returns a hashcode for this IP address.
 *
 * @return a hash code value for this IP address.
 */
 public int hashCode() {
 return holder().getAddress();
 }

 /**
 * Compares this object against the specified object.
 * The result is {@code true} if and only if the argument is
 * not {@code null} and it represents the same IP address as
 * this object.
 * <p>
 * Two instances of {@code InetAddress} represent the same IP
 * address if the length of the byte arrays returned by
 * {@code getAddress} is the same for both, and each of the
 * array components is the same for the byte arrays.
 *
 * @param obj the object to compare against.
 * @return {@code true} if the objects are the same;
 * {@code false} otherwise.
 * @see java.net.InetAddress#getAddress()
 */
 public boolean equals(Object obj) {
 return (obj != null) && (obj instanceof Inet4Address) &&
 (((InetAddress)obj).holder().getAddress() == holder().getAddress());
 }

 // Utilities
 /*
 * Converts IPv4 binary address into a string suitable for presentation.
 *
 * @param src a byte array representing an IPv4 numeric address
 * @return a String representing the IPv4 address in
 * textual representation format
 * @since 1.4
 */

 static String numericToTextFormat(byte[] src)
 {
 return (src[0] & 0xff) + "." + (src[1] & 0xff) + "." + (src[2] & 0xff) + "." + (src[3] & 0xff);
 }

 /**
 * Perform class load-time initializations.
 */
 private static native void init();
}